fix(P0-001): add missing typescript-eslint dep, format all files

Add typescript-eslint to root devDependencies (required by eslint
flat config). Run prettier across all files. Exclude QA reports
from git.

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

.mosaic/orchestrator/config.json

@@ -14,9 +14,5 @@
     "timeout_seconds": 7200,
     "max_attempts": 1
   },
-  "quality_gates": [
-    "pnpm lint",
-    "pnpm typecheck",
-    "pnpm test"
-  ]
+  "quality_gates": ["pnpm lint", "pnpm typecheck", "pnpm test"]
 }